Water-siren.



H. HECHT.

WATER SIREN.

4APPLICATIIIIII FILED OCT. 26. ISII. 4 E,162,719. A Patented Nov. so, 1915.

3 SHEETS-SHEET 1.

MTM E5 5.55

H. HECHT.

WATER SIREN.

APPLICATION FILED ocT. 26. IsII.

,1 62,7 1 9.` PatelIIea Nov. 3o, 1915.

3 SHEETS-SHEET 3.

n lli 'r or f on wA'rEnfsInEN.

To all whom t may concern:

Be it known that I, HEINRICH HECHT, a subject of the Emperor of Germany, and residing at 62 Holtenauerstrasse, Kiel, Germany, have invented certain new and useful Improvements in llVater-Sirens; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to water sirens driven by electric motors, and particularly to one 'well adapted for intermittently producing a. note of uniform pitch under water,

whereby predetermined submarine signals may be eiiiciently transmitted to suitable receivers at will.

In operating water sirens heretofore it has been difficult `tomaintain the note of the siren at the same pitch throughout theA emission of a signal, because the driving load imposed on the motor varied and consequently the speed of rotation of the motor and the drum or rotor of the siren varied, depending upon whether the sound orifices were opened to sound a signal or were :losed at silence'. l

In Vmy co-pending application filed of aven date herewith, the rotor of the siren s continuously driven by a motor of 4any iuitable type, and the additional load im# oosed on the motor in` forcing the rotor zhrough the stream of water issuing from ;he sound orifices to produce a signal is :ompensated for by various mechanical derices when thewater is shunted through the :econdary outlets. In this way the load is maintained constant at all times and'thereore the. speed of rotation and the pitch of he signal are uniform throughout.

In accordance with this invention theA roor of the siren is continuously driven Vby an lectric motorand the' speed of rotation is maintained constant with eXactness by adusting the electric supply to the motor siriultaneously with the change in load. In his way the pitch of the signal of the siren iay be adj usted throughout a wide range to ccord with a tuned receiver, and at any adustment the speed and therefore the pitch f the-siren is maintained absolutely contant from the beginning to the end of the ignal and also when the siren is silent. In ther words this invention discloses means Speciiication of Letters Patent.

Patented Nov; 30, 1915.

Application filed October 26, 1911. Serial No. 656,903.

vthe change in the current supply to the motor.

In the accompanying drawings illustrating for example the application of a direct current shunt wound electric motor in accordance with my invention, Figure 1 shows in cross section, a continuously driven drum siren wherein the adjustment of speed to accord with the change iny load is effected by a variation in the current'supply to the armature of the motor; Fig. 2 shows a similar arrangement except that the adjustment ofspeed is effected by a variation of the current supply to the field winding of the'motor; and in Fig. 3 there is `shown the application to the purpose of my invention of an Y adjustable speed shunt-wound motor of known characteristics.

In the drawings the sound orifices of the slren are open 1n the posltion to produce a signal.

In Figs. 1 and 2, A is a siren and B isa direct current shunt-wound electric motor operatively connected to 'the rotor of the siren in any suitable way. The contact terniinalsV C, are-arranged so as to short circuit the adjustable resistance D, when kthey are in contact with each other, and to allow the current to How through the resistance D to the armature in Fig. 1 or to the field winding in Fig. 2 when they are separated from each other. The adjustable contact T may be connected at will to any part of the resistance' D to accord with the change in circuit required to maintain the speed of the motor constant at the desired value when the load imposed on the motor is changed by opening or closing the sound orifices of the siren. The 'stationary parts of the siren comprise a casing a opening toward the surrounding water, and a .stationary cylinously fed at ope end with water under pressure from any suitable source. On the outlet side of the casing I) are provided openings b,.while a series of openings c in the rotor extends around the circumference of the rotor o in line with the openings b. These openings b and c periodically register with each other during the rotation of the rotor, so that when a signal is desired the water passes through them, thereby producing a note in the well known manner. The stationary casing b is surrounded by a sleeve Z having the openings d in registry with the openings b in the position shown in Fig. l, for producing a signal. The sleeve d is connected by a linke with a lever j', so that when the lever is moved the sleeve is turned an amount equal to the width of the orifices b. In one eXtreme position of the lever f the orifices b1 c1, are closed by the metal ofthe sleeve d, whereupon the siren is silent, while in the other extreme position of the lever f the sound orifices c, b1 d, are open, whereupon the .siren emits a signal. The lever f carries 4oneof the contact terminals C while the other of the contact terminals is mounted on, a stationary part of the siren. In Fig. l, when the lever f is moved to the position shown to open the' sound'orifices of the siren to produce a signal, the two terminals C are in contact with one another so that the resistance D, through which the electric current previously owed from the source designated by to the armature of the motor, is short-circuited. In-this way, when an additional load isimposed on the motor as a result of opening the sound orificesof the siren, the current supplied to the armature is increased in such proportion as to maintain the speed of the motor constant irrespective of the increase of load on the rotor of the siren:

The arrangement shown in Fig. 2 differs from that of Fig. 1 in that the contact terminalsC vary the current supply to the field Winding of the motor. In the position shown in Fig. 2, the sound orifices are open to produce a signal while the resistance D is inserted in the. circuit of the field wind- Iings. When the sound orifices are closed'to silence the siren, the contact terminals C are brought together, thereby short-circuiting the resistance D. In this way, when the load an the motor is decreased as a result of opening 'the secondary. outlets of the siren, the eld excitation of the motor isstrengthened to accord with the decrease in load imposed )n the motor, whereby the speed 'of the mo- ;or is maintained constant during both pe- ."iods of signals and silence. :he note produced by the siren may be adiusted to that of a tuned receiver by adjust- The pitch Aof' inglthe normal speed of the motor in any suitable way, as, for example, by changing the amount of resistance R in series With the source of electric supply.

Although I have shown and described a direct current shunt wound electric motor for driving the siren, it is to be understood that my invention is not limited to the employment of such a motor, but-on the contrary I may employ any form of electric motor wherein the speed may be suitably adjusted in any way whatsoever. Thus there are now available shunt-wound electric motors of the interpole type in which the speed lma;1 be set at any desired value within a wide range and will maintain that Value automatically irrespective of considerable variations in the load on the motor. The application of such a motor to th'e purposes of' my invention is shown in Fig. 3, in which uthe siren is shown as in the other figures,

but the contact-carrying part of the lever f is omitted and an interpole shunt-wound motor M having an adjustable field resistance' N is used for driving the rotor. I/Vithl this arrangement the note of the siren may be changed by varying the resistance N, and by virtue of the inherent characteristics of the motor, the speed will remain the same regardless of the variations of load in the periods of' sounding and of silence.

Having thus described my invention, what I claim is:

In combination with lan electric motor, and a water siren operatively connected thereto comprising a rotor having sound orifices and a stator having sound orifices arranged to communicate periodically with the sound orifices of the rotorduring emission of a signal, a slide having sound oriiices arranged to .register with the sound orifices on the stator in one position of the slide and imperforate portions arranged to close the sound 'orifices in another position of the slide, a lever for moving the slide. from one to the other of said positions, a stationary contact terminal anda coperating contact terminal mounted on said lever,

a resistance, and circuit connections to said-k terminals and said resistance suchthat the movement of the lever from one of said po sitions to the other suddenly alters the resistance of the motor to maintain the speed constant during the periods of signaling andsilence.

In testimony whereof Iy affix my signature, in presence of two witnesses.

DR. HEINRICH HECI-IT. Witnesses: v l

J ULIUS ROPKE, PAUL POPPENDIECK.' 

